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 Entered dateSiteRegionReactor typeEvent description
ENS 559221 June 2022 13:58:00Quad CitiesNRC Region 3GE-3The following information was provided by the licensee via email followed by phone call: At approximately 1043 CDT, the Quad Cities Main Control Room was notified that the Scott County Iowa warning sirens were activated in error at 1001 CDT. The sirens were not intentionally activated to notify the public of severe weather or pending emergency. This event is reportable per 10 CFR 50.72(b)(2)(xi), News Release or Notification of Other Government Agencies. This is a 4-Hour Reporting requirement. The Quad Cities NRC Resident has been notified.
ENS 5590823 May 2022 19:15:00LaSalleNRC Region 3GE-5The following information was provided by the licensee via fax: At 1256 CST on 05/23/2022, it was discovered both trains of Control Room Area Ventilation Air Conditioning Systems were simultaneously INOPERABLE. Due to this INOPERABILITY, the system was in a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5590520 May 2022 17:39:00LaSalleNRC Region 3GE-5The following information was provided by the licensee via email: At 0905 CST on 05/20/2022, it was discovered both trains of Control Room Area Filtration and Area Ventilation Air Conditioning Systems were simultaneously INOPERABLE. Due to this INOPERABILITY, the system was in a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5589916 May 2022 19:51:00Peach BottomNRC Region 1GE-4The following information was provided by the licensee via fax: Unit 2 experienced multiple electrical transients resulting in a Group I Primary Containment Isolation Signal (PCIS) isolation and subsequent unit reactor scram. Low reactor water level during the automatic scram caused PCIS Group II and III isolation signals. Following the PCIS Group I isolation, all main steam lines isolated. All control rods inserted and all systems operated as designed. The following additional information was obtained from the licensee via phone in accordance with Headquarters Operations Officers Report Guidance: Peach Bottom Unit 2 automatically scrammed from 100 percent power due to an electrical transient and subsequent PCIS Group I isolation (Main Steam Isolation Valve closure). Unit 2 lost main feedwater due to the PCIS Group I isolation, however, all other systems responded as expected following the scram. High Pressure Coolant Injection is maintaining pressure control while Condensate Pumps are maintaining inventory. The unit is currently stable and in Mode 3. Peach Bottom Unit 3's Adjustable Speed Drives were impacted by the electrical transients and the unit reduced power to 98 percent power. The NRC Resident Inspector was notified.
ENS 5589110 May 2022 23:42:00Quad CitiesNRC Region 3GE-3

The following information was provided by the licensee via fax: At 1359 CDT on May 10, 2022, the 1B LPCI Loop Upstream Injection valve (1-1001-28B) was found to have a motor operated torque switch issue and inadequate lubrication. This issue called into question the ability of the valve to close when required. At 1746 CDT on May 10, 2022, both trains of Unit 1 LPCI were made simultaneously inoperable. TS 3.6.1.3 Condition A required de-activation of 1B LPCI Loop Downstream Injection valve (1-1001-29B) which was completed at 1746 CDT. Because of the de-activation of the 1B LPCI Loop downstream injection valve and LPCI Loop select logic, both trains of LPCI were made inoperable. Due to this inoperability, the system was in a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(V). Unit 1 HPCI and both loops of Core Spray are operable. After further engineering review, it was determined that 1B LPCI Loop Upstream injection valve condition was minor in nature and would not have affected the ability of the valve to close when required. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.

  • * * UPDATE AT 12:32 EDT ON 05/11/22 FROM MARK HUMPHREY TO BRIAN P. SMITH * * *

The following information was provided by the licensee via phone call and email: The last sentence in the second paragraph, "After further engineering review, it was determined that 1B LPCI Loop Upstream injection valve condition was minor in nature and would not have affected the ability of the valve to close when required," has been deleted. The licensee is continuing to follow up on the issue and believes that sentence to be unclear and premature. Notified R3DO (Skokowski).

ENS 5587129 April 2022 20:44:00FitzPatrickNRC Region 1GE-4The following information was provided by the licensee via email: At 1251 EDT on April 29, 2022, while troubleshooting the failure of the High Pressure Coolant Injection (HPCI) Exhaust Drain Pot High Level Alarm to clear, it was discovered that the High Pressure Coolant Injection exhaust line condensate drain system was not functioning as designed to support removal of condensate from the turbine exhaust. This resulted in some water accumulation in the turbine casing. Subsequently, the High Pressure Coolant Injection System was declared inoperable. As a result, this condition is being reported under 10 CFR 50.72(b)(3)(v)(D) as a condition that could have prevented fulfillment of the safety function at the time of discovery.
ENS 5585723 April 2022 16:27:00ByronNRC Region 3Westinghouse PWR 4-Loop

The following information was provided by the licensee via email: At 0854 (CDT) on April 23, 2022, while performing volumetric inspections required by ASME Code Case N-729-6, a rejectable indication on Reactor Vessel Head Penetration 75 Core Exit Thermocouple (CETC) was identified. The indication is located inboard of the J-groove weld and is OD-initiated (outer diameter - initiated). This event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The repair is scheduled during the refueling outage.

  • * * UPDATE ON 04/29/22 AT 1112 EDT FROM BRYAN LYKKEBAK TO OSSY FONT * * *

The following information was provided by the licensee via telephone and email: The rejectable indication on Reactor Vessel Head Penetration 75 Core Exit Thermocouple (CETC) initiated on the outside diameter (OD) of the nozzle in an area that was not surface stress mitigated (peened). The indication was found to be acceptable for continued operation under CFR and ASME requirements and will not be repaired during this outage. The licensee notified the NRC Resident Inspector. Notified R3DO (Ziolkowski).

ENS 558215 April 2022 06:08:00Nine Mile PointNRC Region 1GE-5The following information was provided by the licensee via telephone and email: On 4/5/2022, at time 0223, during maintenance on Feedwater Level Control Valve 2FWS-LV10B, a Feedwater transient occurred resulting in an RPS Automatic Reactor Scram on Low Level (Level 3, 159.3 inches). Following the scram, reactor water level dropped below Level 2 (108.8 inches) resulting in a Group 2 Recirculation Sample System Isolation, Group 3 TIP ((Traversing Incore Probe)) Isolation Valve Isolation, Group 6 and 7 Reactor Water Cleanup Isolation and Group 9 Containment Purge Isolations. All control rods inserted as expected. High Pressure Core Spray and Reactor Core Isolation Cooling initiated and injected as expected. ECCS Systems have been secured and normal reactor pressure and level control has been established for hot shutdown. Nine Mile Point Unit 2 is stable in Mode 3. These 4 hour and 8-hour non-emergency ENS ((Emergency Notification System)) reports are being made in accordance with 10 CFR 50.72(b)(2)(iv)(A), 10 CFR 50.72(b)(2)(iv)(B), and 10 CFR 50.72(b)(3)(iv)(A). The NRC Resident was informed. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: There was no impact on Unit 1.
ENS 5578814 March 2022 18:30:00LaSalleNRC Region 3GE-5The following information was provided by the licensee via fax or email: At 1338 CDT on 3/14/2022, it was determined that a contract supervisor tested positive during a random fitness-for-duty test. The individual's authorization for site access has been terminated. The NRC Resident Inspector has been notified.
ENS 557696 March 2022 00:55:00ByronNRC Region 3Westinghouse PWR 4-LoopThe following information was provided by the licensee: At 2115 CST on March 5, 2022 Byron Station Technical Support Center (TSC) emergency ventilation system supply fan belt failed. This failure affected the ability of the TSC ventilation system to maintain adequate radiological habitability in the event of an emergency with an airborne radiological release. All other capabilities of the TSC are unaffected by this condition. If an emergency was declared requiring TSC activation during this period, the TSC would be staffed and activated using existing emergency planning procedures. If the TSC becomes uninhabitable, the Station Emergency Director would relocate the TSC staff to an alternate TSC location in accordance with applicable procedures. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the discovered condition affected the functionality of an emergency response facility. The licensee notified the NRC resident inspector.
ENS 557231 February 2022 16:24:00LaSalleNRC Region 3GE-5The following information was provided by the licensee via fax or email: At approximately 1328 CST on 2/1/2022, LaSalle Generating Station was made aware of the following event that resulted in additional county emergency sirens sounding. The Grundy County monthly siren test had issues with siren activation from the County's primary controller. The buttons to activate were being pressed, but the intended sirens were not initiating. The Grundy County operator continued to attempt activation unknowingly activating the sirens in the Northeast quadrant several times between 1000-1015 CST. This event is reportable per 10 CFR 50.72(b)(2)(xi), News Release or Notification of Other Government Agencies. This is a 4-Hour Reporting requirement. The LaSalle NRC Resident has been notified.
ENS 557211 February 2022 15:23:00DresdenNRC Region 3GE-3The following information was provided by the licensee via fax or email: At approximately 1025 CST, the Dresden Main Control was notified of Grundy County warning sirens issues during the intended monthly test. The Grundy County scheduled monthly siren test had issues with siren activation from the County's primary controller. The buttons to activate were being pressed but the intended sirens were not initiating. The Grundy County operator continued to attempt activation unknowingly activating the sirens in the northeast quadrant between 1000-1015 CST. This event is reportable per 10 CFR 50.72(b)(2)(xi), News Release or Notification of Other Government Agencies. This is a 4-Hour Reporting requirement. The Dresden NRC Resident has been notified.
ENS 557221 February 2022 15:20:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopThe following information was provided by the licensee via fax or email: At approximately 1025 CST on 2/1/22, the Braidwood Station Main Control Room was notified of a public notification of multiple inadvertent siren actuation affecting Braidwood Station in Will County, Illinois while testing sirens. This event is reportable per 10 CFR 50.72(b)(2)(xi), News release or notification of other Government Agencies. Braidwood NRC Resident has been notified.
ENS 556853 January 2022 17:01:00LimerickNRC Region 1GE-4The following information was provided by the licensee via email: On January 3, 2022, a Licensed Reactor Operator violated the station's Fitness for Duty policy. The employee's unescorted access to Limerick Generating Station has been terminated in accordance with station procedures. The event was determined to be reportable under 10 CFR 26.719(b)(2)(ii). The NRC Resident Inspector has been notified.
ENS 556843 January 2022 15:58:00Calvert CliffsNRC Region 1CEThe following information was provided by the licensee via email: At 1223 (EST) on 01/03/2022, Calvert Cliffs Unit 2 automatically tripped from 100 percent power due to loss of electrical load. The cause is under investigation. The site Senior Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: All rods inserted and decay heat is being removed via the condenser. The plant is in a normal shutdown electrical lineup. There was no impact on Unit 1.
ENS 556192 December 2021 00:58:00Quad CitiesNRC Region 3GE-3At 1847 CST on December 1, 2021, it was discovered that the HPCI (high pressure coolant injection) system was inoperable. Due to this inoperability, the system was in a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(D). The Unit 1 RCIC (reactor core isolation cooling) system was Operable during this time period. There was no impact on the health and safety of the public or plant personnel. The NRC Resident has been notified. Unit 1 HPCI operability was restored at 2110 CST.
ENS 5560924 November 2021 20:24:00GinnaNRC Region 1Westinghouse PWR 2-LoopThis 60-day telephone notification is provided in accordance with 10 CFR 50.73(a)(1) to report one invalid actuation of the Unit 1 Containment Isolation System Train "A" in accordance with 10 CFR 50.73(a)(2)(iv)(A). On October 17, 2021 at approximately 1358 (EDT), a DC breaker was opened to perform an inspection of a Containment Isolation (CI) rack. A CI signal was produced and resulted in a loss of Letdown during filling and venting the Reactor Coolant System (RCS) with the RCS at 344 psig. RCS pressure began to rise, and prompt actions were taken by the Control Room to secure a Charging Pump within 20 seconds. The RCS pressure rise continued and both Pressure Operated Relief Valves cycled at 409.9 psig as designed, lowering RCS pressure. The CI Train "A" was not part of a pre-planned sequence and the event resulted in the invalid actuation of Train "A" Containment Isolation valves in more than one system. All valves functioned successfully. The DC breaker was closed, CI signal reset, and associated CI valves re-opened. All systems functioned as required and returned to normal service. The NRC Senior Resident Inspector has been notified.
ENS 5559721 November 2021 14:28:00Calvert CliffsNRC Region 1CEAt 1046 EST on November 21, 2021, with Calvert Cliffs Nuclear Power Plant Unit 2 in Mode 1 at 100 percent power, the reactor was manually tripped due to lowering levels in both steam generators following a loss of the 21 and 22 steam generator feed pumps. An Auxiliary Feedwater System actuation occurred to restore steam generator water levels. The trip was not complicated, with all systems responding normally. Decay heat is being removed by the Auxiliary Feedwater System. Calvert Cliffs Nuclear Power Plant Unit 1 is unaffected and remains in Mode 1 at 100 percent power. Due to the Reactor Protection System (RPS) actuation while critical, this event is being reported as a four-hour, non-emergency notification. RPS actuation, per 10 CFR 50.72(b)(2)(iv)(B). Additionally, the automatic actuation of the Auxiliary Feedwater System is being reported as an eight-hour, non-emergency notification, Specific System Actuation, per 10 CFR 50.72(b)(3)(vi)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5559319 November 2021 00:50:00FitzPatrickNRC Region 1GE-4On November 18, 2021, during the performance of High Pressure Coolant Injection (HPCI) surveillance testing, 23MOV-19 (HPCI PUMP DISCH TO REACTOR INBD ISOL VALVE) did not go open as expected while performing the sensed low water level portion of the test. The ability to manually open 23MOV-19 from the control room was unaffected as such, the HPCI system remained available for use. Failure of 23MOV-19 to open automatically prevents the HPCI system from performing its safety function as such this condition renders HPCI inoperable but available and is being reported as a condition that could have prevented the fulfillment of the safety function of a system needed to mitigate the consequences of an accident per 10CFR50.72(b)(3)(v)(D). HPCI inoperable placed the licensee in a 14-day limiting condition for operation for Tech Spec 3.5.1.c. The NRC Resident Inspector was notified.
ENS 5557514 November 2021 08:50:00Peach BottomNRC Region 1GE-4At 0525 EST, November 14, 2021, "Unit 2 was manually scammed by operations due to lowering main condenser vacuum. This resulted in PCIS (process control and instrumentation system) Group II/III isolation signals. All control rods inserted, and all systems operated as designed. Unit 3 is unaffected and remains at 100 percent power in Mode 1. The Resident Inspector was notified.
ENS 5552816 October 2021 09:10:00DresdenNRC Region 3GE-3On October 16, 2021 at 0428 CDT, an automatic scram was received on Unit 3 following a turbine trip. All Rods inserted to their full in position. All systems actuated and operated as expected. Unit 3 is being maintained in Mode 3, hot standby. This event is being reported pursuant to 10CFR 50.72(b)(2)(iv)(B), any event or condition that results in actuation of the reactor protection system (RPS) when the reactor is critical. The NRC Resident Inspector has been notified. The event is related to Event Number 55527.
ENS 5552716 October 2021 07:22:00DresdenNRC Region 3GE-3

(An) Unusual Event (was declared) due to a fire in the protected area not extinguished in less than 60 minutes. Main power transformer 3 faulted, the unit auto scrammed, all rods are in. The fire went out at 0622 CDT. (The licensee) is monitoring for re-flash. The unit automatically scrammed and all rods fully inserted. Decay heat removal is through the condenser. Unit 2 is unaffected and remains at 100 percent power. The licensee notified the NRC Resident Inspector and R3 Branch Chief (Riemer). Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), and DHS Nuclear SSA (email).

  • * * UPDATE ON 10/16/21 AT 0848 EDT FROM DAVID KIJOWSKI TO BETHANY CECERE * * *

The Unusual Event was terminated at 0709 CDT. Notified R3DO (Pelke), NRR EO (Felts), IR MOC (Kennedy), DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), and DHS Nuclear SSA (email).

ENS 555044 October 2021 08:05:00GinnaNRC Region 1Westinghouse PWR 2-LoopThe 'A' Steam Generator Narrow Range Water Level went less than 17 percent causing an Auxiliary Feed Water System valid actuation signal. The Auxiliary Feed Water System was in service at the time of the event providing decay heat removal. There was no adverse effect on plant systems. The Steam Generator Narrow Range Water Level was restored to normal operating band. This is being reported per 10 CFR 50.72(b)(3)(iv)(A), which states, 'Any event or condition that results in valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B) of this section, except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation.' (Reactor Coolant System) RCS Pressure 340 pounds and RCS Temperature 340 Degrees F. The NRC Resident Inspector was notified.
ENS 5549225 September 2021 09:16:00Nine Mile PointNRC Region 1GE-2On 9/25/2021 at 0342 EDT, Nine Mile Point Nuclear Station Unit 1 experienced a loss of the Uninterruptible Power Supply (UPS), UPS 162A, which resulted in a loss of Reactor Protection System (RPS) Bus 11. This resulted in an isolation of both No. 11 and No. 12 Emergency Condensers. Emergency Condenser No. 11 was returned to standby on 9/25/2021 at 0420 EDT and Emergency Condenser No. 12 was returned to standby on 9/25/2021 at 0429 EDT. This 8-hour non-emergency report is being made based upon requirements of 10 CFR 50.72(b)(3)(v)(B) which states: 'Licensee shall notify the NRC of any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to: (B) remove residual heat.' The NRC Senior Resident was informed.
ENS 5548423 September 2021 18:46:00LimerickNRC Region 1GE-4During planned testing of the Unit 1 HPCI (high pressure coolant injection) system, flow controller oscillations occurred which prevented successful completion of the surveillance test. Operators secured Unit 1 HPCI and declared the system inoperable. HPCI inoperable placed the licensee in a 14-day limiting condition for operation that was extended to 30 days after their risk-informed completion time evaluation was done. The licensee has notified the NRC Resident Inspector.
ENS 5545510 September 2021 14:45:00Three Mile IslandNRC Region 1B&W-L-LPThis is a four-hour notification, non-emergency for a notification of another government agency. This event is being reported under 10 CFR 50.72(b)(2)(xi) and 10 CFR 72.75(b)(2). At 1055 EDT on 9/10/21, an employee of a site contractor that was performing work under a contract and in possession of the immediate area where the work was being performed, was involved in a material handling accident in the owner controlled area at Three Mile Island. Londonderry Township EMS and Fire responded to render assistance to the individual. Upon arrival to the site, medical personnel declared the individual deceased. The fatality was work related and the individual was outside of the Radiological Controlled Area.
ENS 5542724 August 2021 16:51:00FitzPatrickNRC Region 1GE-4During an extent of condition review of DC control circuits, it was identified there are additional unprotected DC control circuits which are routed between separate Appendix R fire areas. A postulated fire in one area can cause a short circuit and potentially result in secondary fires or cable fires in other fire areas where the cables are routed. The secondary fires or cable failures degrade the degree of separation for redundant safe shutdown trains and are outside the assumptions of the 10 CFR 50 Appendix R Safe Shutdown Analysis. This condition is reportable in accordance with 10 CFR 50.72(b)(3)(ii)(B). Compensatory actions for affected fire areas have been implemented. Design modifications in the affected control circuits are being developed and will be scheduled to correct this condition.
ENS 553963 August 2021 19:48:00DresdenNRC Region 3GE-3At approximately 1539 CDT on 8/3/2021, the Dresden Station Main Control was notified of the inadvertent actuation of 17 full sounding emergency response sirens affected Dresden Station in Will County Illinois, while testing other sirens. Will County EMA inadvertently actuated the sirens on 8/3/2021 at 1440 CDT. This event is reportable per 10 CFR 50.72(b )(2)(xi), News Release or Notification of Other Government Agencies. This is a 4-Hour Reporting requirement. The Dresden NRC Resident has been notified. See related Event Notification #55395.
ENS 553953 August 2021 19:35:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopAt approximately 1539 CDT on 8/3/2021, the Braidwood Station Main Control Room was notified of the inadvertent actuation of 17 Full Sounding sirens affecting Braidwood Station in Will County Illinois while testing other sirens. Will County EMA inadvertently actuated the sirens on 08/03/2021 at 1440 CDT. This event is reportable per 10CFR50.72(b)(2)(xi), News release or Notification of Other Government Agencies. This is a 4 Hour Reporting requirement. The Braidwood NRC Resident has been notified. See related Event Notification #55396.
ENS 5536319 July 2021 18:27:00Nine Mile PointNRC Region 1GE-5On July 19, 2021 at 1316 EDT, an individual experienced a non-work related medical emergency. The onsite fire brigade and emergency medical technicians administered first aid, but the individual was unresponsive. The individual was transported to the local hospital. At 1458 EDT, the local hospital notified the station that the individual was deceased. The individual was outside of the radiological controlled area and was not contaminated.
ENS 553458 July 2021 20:07:00LimerickNRC Region 1GE-4This 60-Day telephone notification is being made per the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) to describe an invalid actuation of containment isolation signal affecting more than one system. On May 13, 2021, during the restoration of the Unit 2 Refuel Floor High Radiation Isolation Logic an invalid isolation signal was received. The condition requiring an isolation signal was verified not to be present prior to restoring the logic; however, it was not recognized that a previous isolation signal was latched in and had not been reset. When the isolation logic was restored, the Primary Containment Isolation System (PCIS) isolated on the invalid signal. The systems successfully completed the isolation per the plant design and plant configuration. The following systems actuated due to the Unit 2 PCIS Group 6C Isolation: - Isolation of Containment Hydrogen and Oxygen Sampling Valves, - Start of the 2A Reactor Enclosure Recirculation System, - Trip of the Units 1 and 2 Refuel Floor HVAC, - Start of the A and B Trains of Standby Gas Treatment Systems. The NRC Resident Inspector was notified.
ENS 5532524 June 2021 14:56:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopThis is an eight-hour, non-emergency notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the Technical Support Center (TSC) supply fan belt had failed, which affects the functionality of an emergency response facility. Corrective maintenance activities will be performed to restore functionality. The work includes replacing the failed belt and restarting the TSC supply fan. The work duration is approximately 8 hours. If an emergency is declared requiring TSC activation during this period, the TSC will be staffed and activated using existing emergency planning procedures unless the TSC becomes uninhabitable due to ambient temperature, radiological, or other conditions. If relocation of the TSC becomes necessary, the Emergency Director will relocate the TSC staff to an alternate location in accordance with applicable site procedures. (The Emergency Response Organization team has been notified of the maintenance and the possible need to relocate during an emergency.) There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector and Illinois Emergency Management Agency have been notified.
ENS 5532021 June 2021 03:06:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopAt 0051 CDT Braidwood Unit 1 experienced an automatic reactor trip due to a generator lockout relay trip and subsequent turbine trip and reactor trip. The cause of the generator lockout relay trip is unknown at this time and is under investigation. Numerous lightning strikes were present in the area during the time of the generator lockout relay trip. Both trains of auxiliary feedwater started automatically following the reactor trip to maintain steam generator water levels. All systems responded as expected with the exception of failure of source range nuclear instruments to automatically re-energize following the reactor trip. Both source range nuclear instruments were manually energized in accordance with station procedures. The main steam dump valves are in service to the main condenser to provide heat sink cooling. The plant is being maintained at normal operating pressure and temperature. AC power is being provided by Offsite Power with the 1B Diesel Generator in standby. 1A Diesel Generator is out of service for planned maintenance. All other safety systems are available. There is no impact to Unit 2. This report is being made per 10 CFR 50.72(b)(2)(iv)(B) for a RPS actuation, 4 hr. notification, and per 10 CFR 50.72(b)(3)(iv)(A) for an automatic actuation of the Auxiliary Feedwater system, 8 hr. notification. The NRC Resident Inspector and Illinois Emergency Management Agency have been informed.
ENS 5526117 May 2021 13:12:00Peach BottomNRC Region 1GE-4

(Peach Bottom Atomic Power Station declared an unusual event due to a) "receipt of a single fire alarm in the Unit 2 drywell and the existence of the fire not verified in less than 30 minutes of alarm receipt." The NRC Resident Inspector and State and Local Authorities were notified. Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email).

  • * * UPDATE ON 5/17/21 AT 1423 EDT FROM BRETT HENRY TO HOWIE CROUCH * * *

At 1355 EDT, the licensee terminated the notification of unusual event. The basis for termination was that the smoke has dissipated and there were no signs of fire. The licensee notified State and Local Authorities and the NRC Resident Inspector. Notified R1DO (Grieves), NRR EO (Miller), and IRD MOC (Grant). Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS Nuclear SSA (email), FEMA NRCC THD (email) and FEMA NRCC SASC (email).

  • * * RETRACTION ON 6/8/2021 AT 1249 EDT FROM JAMES BROWN TO DONALD NORWOOD * * *

Peach Bottom Atomic Power Station is retracting notification EN 55261, 'Peach Bottom - Unusual Event,' based on the following additional information not available at the time of the notification: Following a Unit 2 drywell inspection, analysis of temperature data, and evaluation of equipment in operation; it was concluded that a fire did not exist. The smoke's most likely apparent cause was the result of heating residual oil/grease in the drywell. Peach Bottom reported the condition and entry into the UE initially based on the available information at the time and to ensure timeliness with emergency declaration and reporting notification requirements. The licensee has notified the NRC Resident Inspector. Notified R1DO (Ferdas).

ENS 552406 May 2021 17:05:00LaSalleNRC Region 3GE-5This telephone notification is provided in accordance with 10 CFR 50.73(a)(1) to report an invalid actuation of containment isolation valves in more than one system required by 10 CFR 50.73(a)(2)(iv)(A). On March 10, 2021, at 0815 (CST), during the Unit 2 Refueling Outage (L2R18), while performing a test to verify functionality of an isolation relay following replacement of the relay, a Group 4 isolation signal was actuated. The Group 4 isolation logic affects both the Reactor Building Ventilation (VR) and Containment Vent and Purge (VQ) system (for both units). All equipment responded as designed to the Group 4 isolation, including startup of Standby Gas Treatment (SBGT) to maintain secondary containment pressure (for both units). Investigation determined that the cause of the isolation was an inadvertent contact of the self-retracting grip jumper between two adjacent terminals that caused a short to ground and a blown fuse during the test performance. The fuse was replaced and systems restored as needed for the plant condition. The containment isolation was not due to actual plant conditions or parameters meeting design criteria for containment isolation. Therefore, this is considered an invalid actuation. The NRC Resident Inspector has been informed of this notification.
ENS 5522430 April 2021 07:38:00Peach BottomNRC Region 1GE-4On 4/29/21 at 2354 (EDT), an alarm was received for U2 HPCI Inverter Power Failure. (It was) identified that the High Pressure Coolant Injection (HPCI) flow controller had lost power due to a failure of an inverter. Without the flow controller, HPCI would not auto start to mitigate the consequences of an accident; thus, HPCI was declared inoperable. All other emergency core cooling systems and reactor core isolation cooling (RCIC) system remain operable. HPCI is a single train system with no redundant equipment in the same system; therefore, this failure is reportable as an event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident per 10CFR50.72(b)(3)(v)(d). The NRC Resident has been informed of this notification.
ENS 5514721 March 2021 23:57:00Calvert CliffsNRC Region 1CEAt 2216 EDT on 3/21/2021, Calvert Cliffs Unit 2 was manually tripped from 37 percent power due to lowering level in the 21 Steam Generator. All systems responded per design. Main Feedwater was secured and Auxiliary Feedwater was manually initiated. The Site Senior Resident has been notified. The cause of the lowering level in the 21 Steam Generator is under investigation.
ENS 5514620 March 2021 04:55:00Quad CitiesNRC Region 3GE-3At 20:30 CDT on March 19, 2021, with the Unit 1 in Mode 5 at 0 percent power, an actuation of the Unit 1 Emergency Diesel Generator (EDG) occurred during outage activities on Transformer 12 (T-12) resulting in a trip. The cause of the Unit 1 EDG auto-start was bus undervoltage as a result of the T-12 trip. The Unit 1 EDG automatically started as designed when the Bus 14-1 undervoltage signal was received. This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the Unit 1 EDG. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5513713 March 2021 01:11:00Nine Mile PointNRC Region 1GE-2On March 12, 2021, at 2102 (EST), Reactor Recirculation Pump (RRP) 13 tripped. The cause for the trip is under investigation. Following the RRP trip, the Average Power Ranger Monitors (APRMs) flow bias trips are inoperable due to reverse flow through RRP 13. The APRMs were restored to operable on March 12, 2021, at 2110 (EST) when the RRP 13 Discharge Blocking Valve was closed. This 8-hour non-emergency report is being made based upon requirements of 10 CFR 50.72(b)(3)(v)(A) which states: 'Licensee shall notify the NRC of any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to: (A) Shut down the reactor and maintain it in a safe shutdown condition.' The licensee has notified the NRC Resident Inspector.
ENS 5513412 March 2021 12:12:00Calvert CliffsNRC Region 1CEA licensed operator had a confirmed positive alcohol test during a random fitness-for-duty test. The employee's access to the plant has been terminated. The NRC Resident Inspectors have been notified.
ENS 5513210 March 2021 18:26:00Quad CitiesNRC Region 3GE-3On March 10, 2021, Exelon reported an unpermitted release of a radionuclide (i.e., tritium) into the groundwater within the site boundary at Quad Cities Nuclear Power Station to the Illinois Environmental Protection Agency (IEPA) and the Illinois Emergency Management Agency (IEMA) in accordance with Illinois state regulations. There has been no detection of the release beyond the site boundary. The suspected source for the increased groundwater tritium levels is an onsite water storage tank or pipe; however, an investigation is in progress and the exact cause and source is not yet known. The increase in groundwater tritium concentration does not exceed any NRC regulations or reporting criteria. This notification is being made solely as a four-hour, non-emergency notification for a Notification of Other Government Agency. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 551224 March 2021 04:00:00Calvert CliffsNRC Region 1CEAt time 0323 (EST) on March 04, 2021, it was determined that the Reactor Coolant System (RCS) pressure boundary did not meet the acceptance criteria under ASME, Section XI IWB-3600, "Analytical Evaluation of Flaws." This condition will be resolved prior to plant start up. This event is being reported as an eight hour non-emergency notification per 10 CFR 50.72(b)(3)(ii)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident has been notified.
ENS 5510617 February 2021 11:30:00Nine Mile PointNRC Region 1GE-5
GE-2
A new, not qualified security officer self reported illegal drug use and resigned following a random fitness-for-duty test. The employee's access to the plant has been terminated. The NRC resident inspectors and R1 security inspector were notified.
ENS 5508629 January 2021 02:43:00LaSalleNRC Region 3GE-5This is an eight-hour, non-emergency notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the Technical Support Center (TSC) Supply Fan belt had failed which affects the functionality of an emergency response facility. Corrective maintenance activities are being performed on January 29, 2021 to the TSC HVAC (heating, ventilation, and air conditioning system). The work includes replacing the failed belt and restarting the TSC Supply Fan. The work duration is approximately 12 hours. If an emergency is declared requiring TSC activation during this period, the TSC will be staffed and activated using existing emergency planning procedures unless the TSC becomes uninhabitable due to ambient temperature, radiological, or other conditions. If relocation of the TSC becomes necessary, the Emergency Director will relocate the TSC staff to an alternate location in accordance with applicable site procedures. The Emergency Response Organization team has been notified of the maintenance and the possible need to relocate during an emergency. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The licensee will be notifying the Illinois Emergency Management Agency.
ENS 5506612 January 2021 20:26:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopA corporate supervisor had a confirmed positive during a random fitness-for-duty test. The employee's access to the plants has been terminated. The NRC Resident Inspectors will be notified.
ENS 5504623 December 2020 12:28:00LaSalleNRC Region 3GE-5At 0653 CST on 12/23/20, it was discovered the single train of high pressure core spray was inoperable. Due to this inoperability, the system was in a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). All other emergency core cooling systems were operable during this time. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The high pressure core spray is inoperable because the water lake pump tripped. This inoperability puts the licensee in a 14-day limiting condition for operability.
ENS 550203 December 2020 17:10:00Calvert CliffsNRC Region 1CEAt 0923 EST on December 3, 2020, with Unit 1 in Mode 1 at 100 percent power, an actuation of the Emergency AC Electrical Power System (Emergency Diesel Generator 1A) occurred during normal plant operations. The reason for Emergency Diesel Generator 1A auto start was due to Class 1E 4KV Bus 11 feeder breaker opening. The Emergency Diesel Generator 1A automatically started as designed when the loss of voltage signal on 4KV Bus 11 was received. This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in a valid actuation of the Emergency AC Electrical Power System. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The cause of the 4KV Bus 11 Feeder Breaker opening is unknown at the present time and is under investigation.
ENS 5500217 November 2020 03:40:00ClintonNRC Region 3GE-6At 1918 CST on 11/16/2020, it was discovered both required trains of the Main Control Room Ventilation and Air Conditioning systems were simultaneously inoperable. Due to these inoperabilities, the systems were in a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). Subsequent post-maintenance testing demonstrated that the Division 1 Main Control Room Ventilation system was available at the time of the event and was restored to operable status at 2036 CST on 11/16/2020. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5500016 November 2020 12:13:00LimerickNRC Region 1GE-4During normal plant start up on Limerick Unit 1, reactor pressure was raised above 200 psig prior to unisolating the Unit 1 high pressure coolant injection system (HPCI) which remained inoperable. Per TS 3.5.1, HPCI is required to be operable in Mode 2 above 200 psig. HPCI has since been restored to operable. The NRC Resident Inspector has been notified.
ENS 5499613 November 2020 05:32:00LimerickNRC Region 1GE-4At 0245 EST on November 13, 2020, the Limerick Unit 1 reactor automatically scrammed on a valid Reactor High Pressure signal (1096psig). The Reactor High Pressure signal was caused by the closure of the 1B Inboard Main Steam Isolation Valve (MSIV), causing reactor pressure to rise, exceeding the Reactor Protection System (RPS) setpoint of 1096psig. The shutdown was normal and the plant is stable in Hot Shutdown with normal pressure control via the Main Steam Bypass Valves to the Main Condenser and normal level control using the Feedwater System. The closure of the 1B Inboard MSIV appears to have been caused by a loss of Primary Containment Instrument Gas (PCIG) pneumatic supply to the valve. The licensee notified the NRC Resident Inspector, and will be notifying Berks, Chester, and Montgomery Counties, as well as the Pennsylvania Emergency Management Agency.